Recently, digital broadcasting typified by digital terrestrial broadcasting has been started, and high-definition broadcasting has become a standard. At the same time, as for a video camera for shooting a video image, high-definition shooting is becoming a standard.
As compared with SD (Standard Definition) video up to now, the high-definition video shooting increases the number of pixels sharply. The number of pixels per frame of the full HD video is 1920 by 1080 as compared with that of the SD video of 640 by 480, which is about six times greater than that of the SD video.
In addition, as for a wide area monitor system, an increasing number of systems have come to employ the high-definition video recently. However, since conventional SD video equipment is left in a lot of existing systems, unless the replacement of the systems has been completed, these systems coexist.
For example, in a system with a full HD camera and an SD resolution monitor mixed together, a high-definition video signal usually undergoes reduction to the SD resolution to be displayed on a monitor. This enables the full HD camera and the SD resolution monitor to coexist. Thus, although the user can look out over a visual field of the full HD camera by visual inspection, since the image information is compressed by the reduction, the resolution is reduced by that amount, which is likely to hinder the monitoring operation.
A Patent Document 1 proposes a method that creates a reduced image by reducing the resolution of a high-definition image a full HD camera takes to a resolution corresponding to that of a display device, and executes the following processing to prevent a focusing job or the like from being hindered: extracting a prescribed image area to be focused from the high-definition video signal; creating a video signal for focusing while maintaining the resolution of the image in the extracted area at the resolution of the high-definition video signal; and superimposing the focusing image and the reduced image to be displayed on a monitoring display screen in a juxtaposed manner (placing them at the upper and lower portions) of the screen, for example).
In addition, a Patent Document 2 proposes a method that sets a designated area when transferring image data of a still image; transfers the high resolution image data for the designated area; and transfers low resolution image data for the area other than the designated area.